1. Field of the Invention
The disclosed invention pertains to heat extractors in general and more particularly to those which comprise a section of stove pipe in a heating system.
2. Description of the Prior Art
Numerous devices exist in the prior art for extracting heat from flue gases. These devices are aimed at recovering heat which would otherwise be lost by passage up the chimney. One such device is shown in U.S. Pat. No. 2,816,714. Another is shown in U.S. Pat. No. 2,902,265. Many heat extractors consist of devices which mount in the firebox of a stove or fireplace and pass air through a closed loop to pick up waste heat as in U.S. Pat. No. 3,866,595. Still others are built after the manner of the circulating fireplace wherein an air path is constructed behind the brick lining of the fireplace and air is circulated therein to pick up waste heat from the warm bricks. A variation of this construction is shown in British Pat. No. 785,699.